1. Field of the Invention
The invention relates to an on-board (mounted in a vehicle) navigation system, and more particularly, to an on-board navigation system for informing to a user the degree of the vehicle's approach to a destination.
2. Description of Background Information
Nowadays, on board navigation systems are in practical use, in which map information is stored into memory and the map information is read out from memory and displayed on a display together with the current location of the vehicle, thereby guiding the vehicle to a predetermined destination.
In such an on-board navigation system, it is a relatively easy task to express a distance from the current location to a destination as a numerical value and to display the numerical value on a display, thereby informing to the user the degree of the vehicle's approach to the destination. However, the driver, who has to concentrate on driving and operation of the vehicle in response to changes in running condition, cannot look into the display a long time. As a result, there is a case where even when the distance between the current location and the destination is displayed, the degree of approach to the destination cannot be informed to the driver.
On the other hand, for the driver and passengers, during the vehicle is running when the degree of approach to the destination is informed by time, such an information is more easy to match the human sense rather than the case where it is informed by distance. In order to adequately inform such a degree of approach to the user, the above-mentioned display of the distance by the numerical value only is insufficient.